Octavian Savu1, Liviu Iosif2, Ovidiu Marius Bradescu1, Cristian Serafinceanu1, Raluca Papacocea3, Irina Stoian4. 1. National Institute of Diabetes, Nutrition and Metabolic Diseases 'N.C. Paulescu', Bucharest, Romania. 2. R&D Irist Labmed SRL, Bucharest, Romania. 3. Physiology Department, University of Medicine and Pharmacy 'Carol Davila', Bucharest, Romania. 4. R&D Irist Labmed SRL, Bucharest, Romania Biochemistry Department, University of Medicine and Pharmacy 'Carol Davila', Bucharest, Romania irina_stoian64@yahoo.com.
Abstract
BACKGROUND: We investigated the l-arginine (l-Arg)-nitric oxide (NO) metabolic pathway in the erythrocytes (RBCs) and plasma of subjects with type 2 diabetes at first clinical onset. METHODS: RBCs and plasma were collected from 26 patients with type 2 diabetes at first clinical onset and 19 age-matched non-diabetes subjects as controls. l-Arg content was assayed by capillary electrophoresis. We measured arginase activity and nitrate/nitrite concentrations by spectrophotometry, and glycosylated haemoglobin (HbA1c) by standardized immunoturbidimetry. RESULTS: We found that, when compared with controls, l-Arg content was similar in RBCs while decreased in the plasma of patients with type 2 diabetes. Interestingly, arginase activity was lower in RBCs and increased in plasma of patients with diabetes. NO production was higher in RBCs in patients with type 2 diabetes, while no difference was found in the plasma of our subjects. CONCLUSIONS: l-Arg catabolism is driven mainly towards NO synthesis in RBCs of patients with type 2 diabetes at first clinical onset. The decreased RBC arginase activity could be considered a potential mechanism of increased RBC NO production in early diabetes. Therefore, the RBC pool would represent a potentially compensatory intravascular compartment for endothelial dysfunction in diabetes.
BACKGROUND: We investigated the l-arginine (l-Arg)-nitric oxide (NO) metabolic pathway in the erythrocytes (RBCs) and plasma of subjects with type 2 diabetes at first clinical onset. METHODS: RBCs and plasma were collected from 26 patients with type 2 diabetes at first clinical onset and 19 age-matched non-diabetes subjects as controls. l-Arg content was assayed by capillary electrophoresis. We measured arginase activity and nitrate/nitrite concentrations by spectrophotometry, and glycosylated haemoglobin (HbA1c) by standardized immunoturbidimetry. RESULTS: We found that, when compared with controls, l-Arg content was similar in RBCs while decreased in the plasma of patients with type 2 diabetes. Interestingly, arginase activity was lower in RBCs and increased in plasma of patients with diabetes. NO production was higher in RBCs in patients with type 2 diabetes, while no difference was found in the plasma of our subjects. CONCLUSIONS:l-Arg catabolism is driven mainly towards NO synthesis in RBCs of patients with type 2 diabetes at first clinical onset. The decreased RBC arginase activity could be considered a potential mechanism of increased RBC NO production in early diabetes. Therefore, the RBC pool would represent a potentially compensatory intravascular compartment for endothelial dysfunction in diabetes.
Authors: Natalia Di Pietro; Annalisa Giardinelli; Vittorio Sirolli; Chiara Riganti; Pamela Di Tomo; Elena Gazzano; Sara Di Silvestre; Christina Panknin; Miriam M Cortese-Krott; Csaba Csonka; Malte Kelm; Péter Ferdinandy; Mario Bonomini; Assunta Pandolfi Journal: Mol Cell Biochem Date: 2016-05-20 Impact factor: 3.396